1. Field of the Invention
The present invention relates to an ink set for forming a multilayer, an ink jet recording method, and a printed material.
2. Description of the Related Art
As an image recording method in which an image is formed on a recording medium such as paper based on image data signals, there are an electrophotographic method, a sublimation type and a melt type thermal printing method, an ink jet recording method, and the like.
In ink jet methods, printing devices are low-priced, no plates are needed when printing, and ink compositions may be efficiently used since an image is directly formed on a recording medium by discharging the ink composition to only necessary image parts, therefore, running costs are low especially in the case of small-lot productions. In addition, ink jet methods have low noise and are excellent imaging recording methods, and as a result, have been receiving attention in recent years.
Among these, an ink composition for ink jet recording which is curable by irradiation of radiation such as ultraviolet light (a radiation curable ink composition for ink jet recording) is an excellent method in terms that it has an excellent drying property comparing to a solvent-based ink composition since most of the components of the ink composition are cured by irradiation of radiation such as ultraviolet light and can be printed on various recording media since the image is not readily bleed.
So far, various radiation curable ink compositions for ink jet recording have been proposed and, JP2007-131755A discloses an active energy ray curable ink for ink set in which the polymerizable monomers contain 80 mass % to 99.99 mass % of a monofunctional monomer and 20 mass % to 0.01 mass % of a polyfunctional monomer with regard to the total monomers and also, the mass change ratio is 30 mass % or less when a cured film of the ink is immersed in the ink for 30 seconds.
High speed, high image quality and fixability to a recording medium when ink is ejected and printed on a non-absorbent recording medium such as a plain paper, plastic or the like by an ink jet printer have currently become an important issue.
For the purpose of image uniformity improvement between various recording media, JP2008-100501A discloses an ink set for ink jet recording which includes at least a coloring liquid composition containing at least a polymerizable compound, a photopolymerization initiator and a coloring agent, and an undercoat liquid composition containing at least a polymerizable compound, a photopolymerization initiator, wherein the polymerizable compound included in the coloring liquid composition is made of at least one type of monofunctional monomer and at least one type of polyfunctional monomer, and the amount of the monofunctional monomer in the total coloring liquid composition is 10 mass % to 70 mass % and the amount of the polyfunctional monomer is 10 mass % to 50 mass %.
Improving durability of printed materials has also been an issue.
JP2010-000788A discloses an ink jet printed material in which a transparent protective layer is formed on the surface for the purpose of obtaining an ink jet printed material with excellent weather resistance and durability and which includes a substrate and a pattern layer formed by an ink jet printing on the substrate, wherein the transparent protective layer is formed on the pattern layer, the pattern layer is made of ultraviolet ray curable resin ink cured by ultraviolet irradiation, and the transparent protective layer is made of an electron beam curable resin cured by irradiation of electrons.